Same digits, new number
Write 3816 in your notebook. Swap the first and last digit. Now the number reads 6813.
Loading lab…
Step 1 of 4
- The digits 3, 8, 1, 6 read as 3816.
- Ring the first and last digit.
- Swap them. It now reads 6813.
- Same 4 digits. A different number.
The rule
Every digit has a place — the spot it has in a number. The places are ones, tens, hundreds and thousands.
Each place has its own worth. A 6 in the thousands place is worth 6000. A 6 in the ones place is worth 6.
Move a digit to a new place and its worth changes. So the number changes. The digits stay the same.
Example
In 3816 the 3 is in the thousands place. The 3 is worth 3000. In 6813 the 6 is in that place. The 6 is worth 6000. 6813 − 3816 = 2997. So the number went up by 2997.